Biomaterial Database

Correlation between tremor, voluntary contraction, and firing pattern of motor units in Parkinson's disease. 1974

V Dietz, and W Hillesheimer, and H J Freund

PATIENTS WITH TREMOR OF PARKINSONISM SHOW THREE CHARACTERISTICS OF MOTOR UNIT ACTIVITY: rhythmic spontaneous resting discharge, abnormally low firing rates during voluntary contraction, and consistent differences in firing pattern between small and large motor units. Smaller units discharge once per tremor beat at weak contractions but change into bursts of two or three spikes per beat at stronger forces. Large units are later recruited and fire preferentially once per beat. The large tremor amplitudes can be partly explained by synchronization of unfused twitches of low frequency units which summate more powerfully than the partially fused contractions during physiological tremor, which is about twice as rapid. Tremor is strongly influenced by the force of voluntary contraction. It is strongest at rest or during weak muscular effort and with increasing force becomes continuously of higher frequency and smaller amplitude. Both changes are the consequence of increasing discharge rates of motoneurones at stronger contractions.

UI	MeSH Term	Description	Entries
D009046	Motor Neurons	Neurons which activate MUSCLE CELLS.	Neurons, Motor,Alpha Motorneurons,Motoneurons,Motor Neurons, Alpha,Neurons, Alpha Motor,Alpha Motor Neuron,Alpha Motor Neurons,Alpha Motorneuron,Motoneuron,Motor Neuron,Motor Neuron, Alpha,Motorneuron, Alpha,Motorneurons, Alpha,Neuron, Alpha Motor,Neuron, Motor
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D010300	Parkinson Disease	A progressive, degenerative neurologic disease characterized by a TREMOR that is maximal at rest, retropulsion (i.e. a tendency to fall backwards), rigidity, stooped posture, slowness of voluntary movements, and a masklike facial expression. Pathologic features include loss of melanin containing neurons in the substantia nigra and other pigmented nuclei of the brainstem. LEWY BODIES are present in the substantia nigra and locus coeruleus but may also be found in a related condition (LEWY BODY DISEASE, DIFFUSE) characterized by dementia in combination with varying degrees of parkinsonism. (Adams et al., Principles of Neurology, 6th ed, p1059, pp1067-75)	Idiopathic Parkinson Disease,Lewy Body Parkinson Disease,Paralysis Agitans,Primary Parkinsonism,Idiopathic Parkinson's Disease,Lewy Body Parkinson's Disease,Parkinson Disease, Idiopathic,Parkinson's Disease,Parkinson's Disease, Idiopathic,Parkinson's Disease, Lewy Body,Parkinsonism, Primary
D004576	Electromyography	Recording of the changes in electric potential of muscle by means of surface or needle electrodes.	Electromyogram,Surface Electromyography,Electromyograms,Electromyographies,Electromyographies, Surface,Electromyography, Surface,Surface Electromyographies
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D014202	Tremor	Cyclical movement of a body part that can represent either a physiologic process or a manifestation of disease. Intention or action tremor, a common manifestation of CEREBELLAR DISEASES, is aggravated by movement. In contrast, resting tremor is maximal when there is no attempt at voluntary movement, and occurs as a relatively frequent manifestation of PARKINSON DISEASE.	Action Tremor,Intention Tremor,Resting Tremor,Coarse Tremor,Continuous Tremor,Darkness Tremor,Fine Tremor,Intermittent Tremor,Involuntary Quiver,Massive Tremor,Passive Tremor,Persistent Tremor,Pill Rolling Tremor,Rest Tremor,Saturnine Tremor,Senile Tremor,Static Tremor,Tremor, Limb,Tremor, Muscle,Tremor, Neonatal,Tremor, Nerve,Tremor, Perioral,Tremor, Semirhythmic,Action Tremors,Coarse Tremors,Continuous Tremors,Darkness Tremors,Fine Tremors,Intention Tremors,Intermittent Tremors,Involuntary Quivers,Limb Tremor,Limb Tremors,Massive Tremors,Muscle Tremor,Muscle Tremors,Neonatal Tremor,Neonatal Tremors,Nerve Tremor,Nerve Tremors,Passive Tremors,Perioral Tremor,Perioral Tremors,Persistent Tremors,Pill Rolling Tremors,Quiver, Involuntary,Rest Tremors,Resting Tremors,Saturnine Tremors,Semirhythmic Tremor,Semirhythmic Tremors,Senile Tremors,Static Tremors,Tremor, Action,Tremor, Coarse,Tremor, Continuous,Tremor, Darkness,Tremor, Fine,Tremor, Intention,Tremor, Intermittent,Tremor, Massive,Tremor, Passive,Tremor, Persistent,Tremor, Pill Rolling,Tremor, Rest,Tremor, Resting,Tremor, Saturnine,Tremor, Senile,Tremor, Static,Tremors